Which Black-eyed Susan?

Why we use scientific names

What’s in a name? There’s a beautiful, vulnerable plant that grows locally on the West Ridge, on the low-nutrient soils of the Awaba Soil Landscape. It’s a clumping shrub, with single or multiple stems that stretch 30–60 cm long. The stems are often leafless, edged with narrow wings that give them an angular look. Along the stems, delicate flowers droop downwards, usually in fours, with petals ranging from white to soft pink through to deep purple.

This plant is commonly known as Black-eyed Susan, but its scientific name is Tetratheca juncea, affectionately called TJ.

BUT there’s also an invasive weed with the very same common name. This Black-eyed Susan (Thunbergia alata) is a vigorous perennial climber, scrambling 3–4 metres high . Its triangular leaves form dense mats, while its orange or yellow flowers with dark throats are eye-catching but destructive. After flowering, hairy seed capsules form, helping it spread. More often though, its escape comes via dumped garden waste. On Coal Point it is a major problem, smothering native plants.

And if that wasn’t confusing enough, Rudbeckia hirta, another “Black-eyed Susan,” also known as Yellow Coneflower, hails from North America. It’s a daisy-like plant growing up to a metre tall, with many cultivated varieties.

So we have three very different plants, all called Black-eyed Susan. This is why Landcare uses scientific names. Botanical names cut through the confusion, and once you start using them, it’s a bit like learning a new language. It’s good for the brain, helps us be precise, and even opens the stories behind the names:

• Tetratheca = “four cells or lobes” for the four-petalled flower
• juncea = “rush-like,” describing its long, slender stems

While Tetratheca juncea isn’t currently available for sale, there are many local native plants that make excellent understorey options for home gardens. You can find tubestock at the Lake Macquarie Landcare Nursery, 80 Toronto Road, Booragul, open Tuesdays and Wednesdays, 8.30am–3pm, or by appointment.

All the details on the very special Tetratheca juncea are here 

Alternatives to plant instead of Thunbergia alata are here 

LEAP students lend a hand

Each fortnight during November and December Toronto High School’s year 7 LEAP class ventured out to Coal Point to assist with the surveying of Tetratheca juncea along the West Ridge. 

What a crew! Each session saw 17-21 enthusiastic students, the amazing Ms Havercamp and Mr Banks form into 3 survey groups. The team came out well prepared having researched the threatened species and set up recording proforma for the data entry.

During the first session the teams identified and tagged the TJ clumps. For the next two sessions they recorded the location on GPS and entered the data about the size and weed threats onto tablets. Over a hundred clumps were located and all of the survey data transcribed ready to be uploaded onto Bionet

The THS crew also monitored nestboxes in the survey area and to everyone’s joy a family of Squirrel gliders were recorded in one of the boxes, reinforcing the benefits for additional habitat options.

The THS crew were supported by Joel, Glen and Harvey from TIN’s landcare team who provided surveying and on-ground expertise in weed identification as Formosa lily and Asparagus fern were targeted during the field trips. Additional thanks to Coal Point Public School for providing their facilities for water stops.

BUT WHICH BLACK-EYED SUSAN?

The Invader- Black-eyed Susan

Up along the ridge, our beautiful, threatened Black-eyed Susan, Tetratheca juncea, will be thinking about budding with its pendant blue flowers soon.

Meanwhile, 'the Other' Black-eyed Susan, the Invader, is running rampant through the edges of our bushland and along the foreshore at Threlkled. She is Thunbergia alata, a slender vine that grows about 4m long. She is native to Eastern Africa, and has become an invasive weed species in Australia.

Her bright yellow-orange flowers, with a striking black centre, certainly catch the eye. Her leaves are roughly triangular to heart-shaped, with soft fine hairs and broadly toothed margins.

Roots form at the nodes of the stem when they come into contact with the soil, anchoring the plant and forming new plants. Of course, seeds are also dispersed and germinate far too successfully!

Black-eyed Susan will escape from gardens into bushland and be a huge threat to native vegetation. To keep her under control, gently hand-pull or dig young plants, or spray larger plants.

Good non-invasive native alternatives to Black-eyed Susan are the golden snake vine (Hibbertia scandens) or rich purple native sarsaparilla (Hardenbergia violacea).

The Threatened species Black-eyed Susan

A cornucopia of clumps

Several locals have been reporting Tetratheca juncea out in bloom from as far away as Kilaben Bay Fire trail and Awaba.

Tetratheca juncea

Closer to home a cornucopia of clumps have been located along the West Ridge and documented as part of the Threatened Species project.

Some interesting observations so far have been that the Tetratheca juncea is being found only on the southern side of the Ridge, there are areas where there are multiple clumps in close proximity and then spots where it’s not. It is already starting to set seed and becoming less obvious as the blossoms wither and drop and leave only the leafless stems. 

Once the locations are mapped it will provide an opportunity for targeted bush regeneration to remove the threat of weeds to this ‘at risk’ species. This offer will be available to private landholders who are interested in caring for their clumps.

If you know you have a clump and would like some bush regeneration support contact Suzanne cppa.tsls@gmail.com .

Bioblitz botanical bonanza -Tetratheca time

Whilst out installing nestboxes the eagle eyes of flora focussed fanatics spied some Black-eyed Susan (Tetratheca juncea) in full bloom…most exciting for all concerned, a real botanical bonanza!

This plant is difficult to spot most of the time as its leafless stems are pretty insignificant but these patches were beautiful. The T. juncea plant is a very pretty, delicate low shrub that forms a ‘tussocky clump’, which is slow growing, some bigger clumps are estimated to be more than 100 yeas old.

Tetratheca juncea grows mostly in Eucalyptus woodlands on low nutrient soils in association with fungi filaments (mycorrhiza) and around Coal Point it is in the Coastal Foothills Spotted Gum Ironbark Forest ecotone, this is the vegetation community along the ridge.

Nationally the species has a very restricted range with only two meta-populations, in the Central Coast and North Coast areas. The Lake Macquarie LGA is part of the Central Coast population.

Tetratheca juncea is a bit of a ‘toughy’ known to withstand slashing and nearby clearing and it can even persist in areas of weed invasion but weed infestation over the long-term appears to gradually diminish the size of the T. juncea population. Dumping of garden waste into reserves is the biggest local threat to its ongoing survival.

T.juncea is listed as a threatened species under both the NSW Threatened Species Conservation Act 1995 and the Commonwealth Environment Protection and Biodiversity Act 1999. It is also listed as a Rare Or Threatened Australian Plant (ROTAP) with status 3VCa. 

Factual information above was gleaned from Table 1 Summary of important characteristics of T. juncea in the Lake Macquarie T juncea Planning and Management Guidelines 2014.

The Threatened Species Last Stand on the Coal Point peninsula project has funds available to cover the cost of some bush regeneration on private land for landholders who have Tetratheca juncea on their block.  Now is the time to have a good look for it because its flowering is peaking. 

Recently a 2 hour survey along the West Ridge located 10 clumps in a relatively small area. A significant population by national standards, would mean 20 clumps/hectare. 

Do you know where there are T juncea clumps? 

Would you like some bush regeneration support? 

Please contact Suzanne to share the joy.

TSLS Project Update

September, being Biodiversity Month, saw a lot of activity under Threatened Species Last Stand on the Coal Point Peninsula project.

The inaugural BioBlitz was attended by 21 locals who found out a little bit more about the local birds, local plants, night-time critters and habitat hollows. 

Two presentations on wildlife corridors were delivered to the Carey Bay preschoolers who were well aware of the importance of trees and found out about how tree canopies help animals to move through the neighbourhood. (Congratulations to the preschool community for achieving excellence in their recent accreditation process!)

Stalls were held at Blue Gum Hills Biodiversity Day and the Living Smart Festival to help spread the word and connect kids with nature through seed craft and treasure hunts and a poster presentation was created for the State Landcare forum.

Weekly Landcaring has been continuing every Thursday with Burnage Reserve the recipient of the bush regen benefits and additional support from volunteers from Trees In Newcastle(TIN) and Lake Macquarie Landcare’s Green team in the past month.

TIN bush regenerators have been busy too… at the remnant bushland link between Hampton St and Laycock St, targeting freesias on the West Ridge Reserves and lending a hand at the BioBlitz. In the coming month they will be focussing on the threatened plant, Tetratheca juncea (TJ) which is in bloom at the moment so it’s easy to spot. The aim is to give the TJ a helping hand by reducing the local the weed competition. 

If you know of any Tetratheca juncea patches that need help please make contact with Suzanne by email coalpointprogress@gmail.com  and the help will be allocated.

Heading in to Year 2 of the project the focus for bush regeneration support will be shifting to assist local landholders who live adjacent to the public reserves with their weed management and corridor creation.  

Several neighbourhood nodes have already been identified and weekday and weekend bush regeneration support is available. It is not too late to be included in the project. Support is available for bush regeneration, nest boxes and their installation and discount native plant purchases.

Additionally there has been a flurry of neighbourhood activity behind the scenes as some locals have been wondering how to protect the corridor around Carey Bay.